Caption: Transgenic rice research. Rows of transgenic rice plants being cultivated in a greenhouse. Transgenic plants are ones that have been genetically modified by adding genes from different species. For crop plants such as rice, the added genes usually promote resistance to pests and disease, or promote improved growth or other characteristics. Cultivated rice (Oryza sativa) is a key food crop, forming the staple diet of around half the world's population. Photographed at the French agricultural research institute, CIRAD, in Montpellier, France.